I believe that's because it acts like a giant cholea ( like what we have inside our ears ) as the air circulated thru the chambers it creates a sound effect like the ocean
I believed it had something to do with blood vessels from your ears reflecting sounds trapped inside a curved seashell...
may be there is an ocean insiad.
i have always wonder why it sounds like the ocean also and I always thought because the shell was in rhe ocean for so many years the sound of the ocean has become a part of the shell.
I read this question before. It is a copycat.
Why would I be the copy cat if I already answered this question before. I don't have to prove myself to anyone.
My apologies as well. I should have known that many come to this site. New and old; and just because the question was old doesn't mean that you are new here. My respects and I will remember this the next time. Forgive me for my stupid response and I accept that I was wrong. And this is over with apologies. Peace! This was my fault and not yours. Again; sorry and it's forgotten.
ambient noise from around you. The seashell that you are holding just slightly above your ear captures this noise, which resonates inside the shell. The size and shape of the shell therefore has some effect on the sound you hear. Different shells sound different because different shells accentuate different frequencies. You don't even need the seashell to hear the noise. You can produce the same "ocean" sound using an empty cup or even by cupping your hand over your ear. Go ahead and try it and vary the distance at which you place the cup near your ear. The level of the sound will vary depending on the angle and distance the cup is from your ear.<br />
Noise from outside the shell also can change the intensity of the sound you hear inside the shell. You can look at the shell as a resonating chamber. When sound from outside enters the shell, it bounces around, thus creating an audible noise. So, the louder the environment you are in, the louder the ocean-like sound will be.<br />
It's part of "God's plan"...
it something related to physics and i m weak in it,sorry